Lift truck



A. M. BARRETT May 8, 1934.

LIFT TRUCK A Filed Dec. v9. 1932 5 Sheets-Sheet l May 8, 1934. A. M. BARETT 1,958,292

LIFT TRUCK Filed Deo. 9, 1932 3 Sheets-Sheet 2 y s "3 s N 6 o e o QQ :i lo N N O N.. i ia lu E J) wl o KQ/ O u N A. M. BARRETT May 8, 1934.

LIFT TRUCK Filed Dec. 9. 1932 3 Sheets-Sheet 3 Patented May 8, 1934 UTEQ SATES LIFT TRUCK poration of Illinois Application December 9, 1932, Serial No. 646,467

13 Claims.

This invention relates to lift trucks of the class described in patents to Arthur M. Barrett, Nos. 1,829,726, 1,803,688, 1,773,935, 1,773,934, 1,707,971, 1,633,390, 1,551,630, 1,528,749, 1,459,044, 1,428,522, 1,416,675, 1,416,674, 1,308,750, 1,125,634, and patents to W. T. Johnson, No. 1,488,882; Barrett, Childress and Trott, No. 1,428,523; and Childress, No. 1,402,480.

The purpose of the present invention is to provide such equipment with means for varying the effective height of the load carrying platform of the truck, according to the height of the skids or other articles underneath which the truck is pushed, before the load is lifted. Means are provided for effecting this adjustment automatically by engagement of a shoulder on the truck with the load. A further purpose of the invention is to utilize the maximum extent of load lifting possible with the truck, solely for load lifting, and to provide separate means for adjusting the load carrying surface to the height of the under surface of the object to be lifted.

The objects of the invention are accomplished by means of a construction illustrated by the drawings, in which:

Figure 1 is a plan view of the improved truck.

Fig. 2 shows the truck in side elevation.

Fig. 3 is a perspective View of a load carrying skid such as commonly used in connection with this class of trucks.

Fig. 4 is a side view according to Fig. 2, but with the load carrying platforms in upper positions.

Fig. 5 is a transverse sectional view taken on the line 5 5 of Fig. 4.

Fig. 6 is a plan view of a modification of the structure illustrated by Figs. 1, 2, 4 and 5.

Fig. 7 is a side elevation of the construction illustrated by Fig. 6. In this drawing the load carrying platforms are shown in their lowermost positions.

Fig. 8 is similar to Fig. 7 except that the load carrying platforms are shown in raised positions.

Fig. 9 is a fragmentary sectional detail to illustrate a release means for the auxiliary load carrying platform of the modification illustrated by Figs. 6 to 8.

Fig. l0 is a sectional View taken on the line 10-10 of Fig. 8.

The improvements are illustrated and described in connection with a manually operated truck but are also applicable to powered vehicles.

The general arrangement of trucks of the class illustrated is a Wheeled frame structure upon which is mounted, generally by parallel links, a

load carrying platform or frame which may be adjusted on the wheel frame upwardly to lift the load, and generally by means of a connection with the tongue or handle used for pulling the truck when the handle is oscillated in a vertical plane. There is generally clearance between the load lifting platform, when in its lower position, and the underneath surface of the skids, such as illustrated by Fig. 3, upon which the load rests. To take up this clearance by raising the load lifting platform of the truck by means of the ordinary lifting mechanism with which the truck is equipped, lessens to this extent the maximum effective lift which may be attained. The truck is therefore by this invention equipped with separate means by which the load carrying platform or an auxiliary load carrying platform of the truck may be adjusted to the load before the lifting means is operated. The maximum lift may then be effected without lost motion, and the maximum floor clearance is maintained.

The improvement consists in equipping the normal load carrying frame of the truck with an auxiliary frame which may be adjusted preferably by engagement with the load carrying skid when the truck is pushed beneath the skid.

This improved construction, as illustrated in Figs. 1, 2, 4 and 5, is a rectangular frame 1, which is auxiliary to the usual load carrying frame 2, and is illustrated in Fig. 1 as surrounding the frame 2, except that the forward cross-frame element 3 bridges over the frame 2 and affords a shoulder 4 for engagement with one end of a load supporting skid 5, shown in Fig. 3. When the truck is pushed beneath the skid far enough for the shoulder 4 to engage the end of the skid, the auxiliary load carrying frame 1 is shifted from the full line position in Figs. 1 and 2, to the broken line position in Fig. 2.

Inclined guide bars 6 secured to auxiliary frame 1 guide the frame upwardly in an inclined path by sliding along the inclined supports 7 secured to the main load carrying frame 2. Displacement of the auxiliary load carrying frame 1 rearwardly with reference to the supporting elements 7 is prevented oy the inclined bars 9 vin alinement with the bars 6, and also attached to the main load frame 2. The auxiliary frame 5 is retained in its lift position by ratchet bar 10, pivoted to the cross frame member 4 and co-acting with the toothed element 11 mounted upon the cross frame angie bar 12 of frame 2.

The latter frame is supported on a truck frame 13 by means of parallel links 14 and 15. In lifting the load, frames 1 and 2 move upwardly and forwardly as a unit around the pivotal connections between the links 14 and 15 with the truck frame 13, and are so shifted by means of a lifting yoke 16 extending between the main load carrying platform 2 and the link connection 17 with the lever 18 operated by a tongue or draft handle 19.

The lifting leverage connection, together with latching and releasing mechanism, and the cushioning dashpot 20, are all old in the art, and therefore are not now described in detail. The dashpot mounting, however, varies from that described in prior above-mentioned patents, in that instead of a connection between the truck frame 13 and the main load carrying frame 2, it is connected between the truck frame 13 and the auxiliary load carrying frame 1. But its function is the same, as it regulates the rate of descent of the load carrying structure.

In the present arrangement, both frames 1 and 2 may be released as a unit, and lowered together; and frame 1, when desired, may be further lowered singly. Io release the auxiliary frame 1 and permit it to lower with reference to frame 2, the ratchet bar 10 is swung out of engagement with the toothed element 11 on frame 2, by means of a foot operated pedal 2l, attached to shaft 22, which carries a cam element 23 for engagement with ratchet bar 10. Supporting brackets 24 for shaft 22 are carried by frame 2.

The modification illustrated by Figs. 6 to 10 inclusive, is essentially the same as that illustrated by Figs. 1, 2, 4 and 5, and corresponchng elements bear the same reference numerals.

In these figures, however, the latching ratchet bar 10 is omitted and retaining teeth are cut in the inclined side bar 6 attached to auxiliary frame 1, and coacting teeth are cut in a guide 7 attached to the main load supporting frame 2. Thus, when auxiliary frame 1 is raised by engagement with the load to be lifted, it ratchets up over the guide 7', and is retained in its lifted position thereby. To release frame l from frame 2, the rear end of the frame is pushed upward by means of a cam 22, slidably supported on frame 2 and coacting with the fixed cam element 23 on frame 1.

Cam element 22 is operated by a pedal 24, pivoted to a cross member of frame 2 and connected with the cam by a rod 25.

In this operation of this truck, the auxiliary load carrying frame 1 is adjusted to the lower surface of the load by pushing the truck underneath the object to be lifted far enough for shoulder 4 to shift from the full line position, Fig. 2, to the broken line position, thus sliding the auxiliary frame upwardly and forwardly as guided by the inclined supports 7 on frame 2. It is latched in its upper position by teeth on rack l0 engaging tooth 11, or as in the form illustrated by Fig. '7, by the teeth on member 6 engaging teeth on member 'l'.

The load lifting is effected by raising load frames 2 and 1 as a unit. Again in lowering the load to the floor, platforms l and 2 may be released to lower as a unit merely by releasing platform 2. It is not necessary to again adjust platform 1 with reference to platform 2, except when the truck is to be used for different work, for instance, in connection with skids 5 of different height.

I claim:

1. A lift truck comprising a wheeled frame structure, a lifting frame adjustably mounted thereon, and means on said lifting frame for effecting an adjustment of said lifting frame with reference to the lower surface of an object to be lifted thereby, which means is operative by engagement with said object when the truck is moved in a horizontal position, and means to latch said lifting frame in substantially any position to which it may be adjusted by such engagement.

2. A lift truck comprising a wheeled frame structure and lifting frame adjustably mounted on said wheeled frame structure, and an auxiliary lifting frame adjustably mounted upon said lifting frame, and means operative to adjust said auxiliary frame when the truck is moved horizontally into engagement with the object to be lifted.

A lift truck comprising a wheeled truck frame, a main lift frame adjustably mounted upon said truck frame, an auxiliary frame supported in inclined ways on said main lift frame, and a projection upon said auxiliary lift frame which shifts the auxiliary frame on said inclined ways by engagement with the object to be lifted.

4. A lift truck comprising a wheeled truck frame, a main lift frame adjustably mounted upon said truck frame, an auxiliary frame supported in inclined ways on said main lift frame, and a projection upon said auxiliary lift frame which shifts the auxiliary frame on said inclined ways by engagement with the object to be lifted, and means for releasably retaining the auxiliary lift frame in adjusted position.

5. A lift truck comprising a wheeled supporting frame having a steering mechanism including a tongue pivotally connected thereto, a main lifting frame adjustably mounted on said supporting frame, an auxiliary lifting frame mounted on said main lifting frame and vertically adjustable relative thereto, means operative by horizontal engagement of said truck with the object to be lifted tc adjust said auxiliary frame, and means operable by said tongue to adjust said main frame.

6. A lift truck comprising a wheeled supporting frame having a steering mechanism including a vertical steering post operable by a tongue pivotally connected thereto, a lifting frame mounted on said supporting frame, means operable by said tongue for raising said lifting frame relative to said supporting frame, an auxiliary frame supported by said lifting frame, and means independent of the first named means for adjusting said auxiliary frame vertically relative to said lifting frame and into engagement with the object to be lifted.

7. A lift truck comprising a wheeled frame structure and lifting frame adjustably mounted on said wheeled frame structure, an auxiliary frame adjustably mounted upon said main lifting frame, and means operative to adjust said auxiliary frame when the truck is moved hori- Zontally into engagement with the object to be lifted.

8. A lift truck comprising a wheeled supporting frame, a main lifting frame adjustably mounted on said supporting frame, an auxiliary frame adjustably mounted on said main lifting frame, and a cushioning means connected between said auxiliary frame and said wheeled supporting frame.

9. A lift truck comprising a wheeled frame structure and a lifting frame adjustably mounted on said wheeled frame structure, an auxiliary frame adjustably mounted upon said main lifting frame, means operative to adjust said auxiliary frame when the truck is moved into horizontal engagement with the object to be lifted, and a cushioning means connected between said auxiliary frame and said Wheeled frame structure.

10. A lift truck comprising a wheeled truck frame, a main lift frame adjustably mounted upon said truck frame, an auxiliary frame adjustably supported on said main lift frame, means operative to adjust said auxiliary frame when the truck is moved into horizontal engagement with the object to be lifted, means for releasably retaining the auxiliary frame in adjusted posi tion, and a cushioning means connected between said auxiliary frame and said wheeled truck frame for cushioning said auxiliary frame upon its being released.

ll. A lift truck comprising a wheeled truck frame, a main lift frame adjustably mounted upon said truck frame, an auxiliary frame supported in inclined ways on said main lift frame, means to shift said auxiliary frame on said in clined ways by engagement with the objects to be lifted, means for releasably retaining the auxiliary frame in adjusted position, and means connected between said auxiliary frame and said wheeled truck frame for cushioning said auxiliary frame upon its being released.

12. A lift truck comprising a wheeled frame structure having a steering mechanism including a tongue pivotally connected thereto, a main lifting frame adjustably mounted on said wheeled frame structure, means operable by said tongue for adjusting said lifting frame, an adjustable auxiliary frame arranged to be adjusted vertically by horizontal engagement with the object to be lifted, and a cushioning means connected between said auxiliary frame and said wheeled frame structure.

13. A lift truck comprising a wheeled supporting frame, a main lifting frame adjustably mounted thereon, a vertically adjustable auxiliary lifting frame mounted upon said main lifting frame, a draft handle, and means for effecting the vertical adjustment lof each of said frames through manipulations of said draft handle.

ARTHUR M. BARRETT. 

